What is the test point used for?

The test point is a way to determine if the
cable is energized. The voltage test point is not intended for actual voltage
measurements or phasing operations and has no direct connection to the
conductor. It uses an impedance capacitance tap and only voltage indicating
instruments designed for this application to establish the presence of
voltage should be used. A voltage reading will indicate the presence of
voltage, but a reading of no voltage is not sufficient to establish a
de-energized circuit before touching the connector. Other procedures should
be implemented to establish a de-energized circuit.